In many industrial applications, there is a need to control the temperature of a target. One such application is plasma processing in semiconductor device fabrication. A typical plasma processing apparatus includes a wafer processing chamber and a pedestal disposed in the wafer-processing chamber. The pedestal typically includes a chuck for holding a semiconductor workpiece or wafer. In the plasma processing apparatus, plasma formed with excited process gasses is used to etch or deposit layers of materials on the semiconductor workpiece or wafer. The plasma may additionally cause heating of various components of the plasma processing apparatus and/or the workpiece, which can undesirably affect the precision and repeatability of the processes performed by the plasma processing apparatus.
As feature sizes continue to decrease, there is an ever-increasing need to provide better temperature control to plasma processing apparatus in order to provide consistent and precise fabrication of semiconductor devices. For example, in plasma etching, a number of parameters within the wafer processing chamber need to be tightly controlled to obtain specified results, such as etch rate, etched feature profile, etch selectivity to underlying layers, etc. The parameters include the temperature of the chuck, the wall(s) and/or any other component of the wafer-processing chamber. Generally, the tolerance of the plasma processes used to fabricate semiconductor devices and the performance of the resulting semiconductor devices can be highly sensitive to temperature fluctuations during the plasma processes. Therefore, it is desirable to have a temperature management system and method that can achieve very accurate temperature control of the workpiece and/or components of the plasma processing apparatus.